The reagents used in Ziehl–Neelsen staining method are carbol fuchsin (primary stain), acid alcohol and methylene blue (counter stain). The Kinyoun staining method uses carbol fuchsin as a primary stain, followed by decolourization with an acid-alcohol solution and methylene blue as a counter stain.

Enterobacter and Staphylococcus are examples of catalase-positive bacteria.

The Gram stain technique distinguishes between Gram-positive and Gram-negative bacteria by colouring these cells purple or pink. Gram-positive bacteria stain purple due to the presence of a thick layer of peptidoglycan in their cell walls, which retains the crystal violet of these cells during the decolouring process. Gram-negative bacteria stain pink, which is attributed to a thinner peptidoglycan wall, which does not retain the crystal violet during the decolouring process.

Rhodospirillum is a genus of purple non-sulphur photoautotrophic bacteria of the family Rhodospirillaceae.

Transduction method of genetic recombination in bacteria, e.g. Salmonella typhimurium was first demonstrated by Zinder and Lederberg in 1952. It is the transfer of genes (small double stranded piece of DNA) from one bacterial cell to another via virus (bacteriophage).

Myxobacteria and Cytophagales are called gliding bacteria on the basis of their gliding mobility on solid surfaces.

Safranin is used as secondary stain (counter stain) in Gram staining technique and carbol fuchsin is sometimes substituted for safranin as counter stain since it stains anaerobic bacteria more intensely.

Amphitrichous: Flagella at both sides or ends, e.g. Nitrosomonas

Peritrichous bacteria have flagella projecting in all directions (e.g. Escherichia coli). Lophotrichous bacteria have multiple flagella located at the same spot on the bacteria's surfaces (e.g. Helicobacter pylori). Amphitrichous bacteria have a single flagellum on each of two opposite ends (e.g. Rhodospirillum rubrum). Monotrichous bacteria have a single flagellum (e.g. Vibrio cholerae).

Nocardia is an obligate aerobe.

Ziehl-Neelsen stain is used to identify the acid-fast bacteria, mainly Mycobacterium.

Beggiatoa is a genus of chemosynthetic filamentous sulphur-oxidizing bacteria.

Lactobacillus and Listeria are non-spore forming rods.

Membrane bound organelles like endoplasmic reticulum, mitochondria and golgi bodies are absent in bacteria. Bacterial nucleus is of primitive type (prokaryotic), i.e. without nuclear membrane and nucleolus.

Leaf blight of rice is caused by Xanthomonas oryzae. Angular leaf spot of cotton is caused by Xanthomonas campestris. Halo blight of bean is a bacterial disease caused by Pseudomonas syringae. Bacterial sheath rot of wheat is caused by Pseudomonas fuscovaginae.